For the convenience of maintenance, base station in recent years usually comprises a proximal end, i.e., a main unit (MU) or a base band unit (BBU); and a distal end, i.e., a remote radio unit (RRU). The two portions are connected via fibers. The MU can be mounted at an appropriate machine room position, and the RRU is mounted at the antenna end (the distal end). In this way, the previous integral base station can be divided into two portions separated from each other, and the fussy maintenance work can be simplified. One MU can be connected to multiple RRUs, which not only saves the machine room space but also reduces the maintenance cost, and increases networking efficiency. 3G network uses larger amount of distributed base station frameworks and adopts multi-channel schemes of MU+RRU, so that large area of indoor coverage can be primly achieved.
However, the RRUs in the current market are all integrally manufactured in the form of a single piece as shown in FIG. 1 exemplarily, wherein a heat sink structure 14 serves as a casing for accommodating a filter unit 13 and several radio printed circuit boards (PCB) 11, 12 therein integrally so as to provide environmental protection for all these components. Thus, when one component of the RRU needs replacing due to malfunction or needs updating for technical upgrade or parameter adjustment, only the entire RRU can be replaced by another RRU integrally, instead of only partially replacing one or more of the filter unit 13 and the radio PCBs 11, 12 of the RRU that need replacing.
The current RRU providers mostly pay their attention to how to divide these components within the heat sink structure and arrange them compactly within the heat sink structure, while ignoring the future scalability of the RRU, maintenance costs and so on. Hence, it is desiderated to improve the current RRU structure design.